In July 2006 the demise of Girls Aloud was a tabloid splash. "They just don't talk at all. It's all over," reported the News of the World. The villain was Cheryl Tweedy, her head supposedly turned following a World Cup trip to Germany with the England squad "Wags". So far, so predictable – the surprise came when the split didn't happen. The group enjoyed further hit albums and critical adoration. And Cheryl Tweedy is now Cheryl Cole, tearful nice-cop of Saturday evening TV and – since the kiss-and-tell stories involving husband Ashley – Britain's favourite wronged woman.

The shift in the media's presentation of Cole has been remarkable. From a Geordie brawler and apprentice Posh Spice she has turned into a beloved young star, forever "in torment" on weekly magazine covers but still able to tap limitless reserves of empathy. "In these times of doom and gloom," the editor of Grazia said last year, "all we want is a hug from Cheryl."

Few need that hug more than record industry executives, and the Dianafication of Cole means this debut album is the most high-profile pop record of 2009 – flop-proof in a way girl-group solo records rarely are. Lead single Fight for This Love – set to be the fastest-selling single of the year – bears this out. Initially it's underwhelming: hollow drum sounds and a shuddering keyboard create a subdued backdrop for Cole's flinty vocal. But it has two big commercial advantages. First of all, it's deceptively catchy. Second, people can easily imagine it's about Ashley Cole.

Cheryl Cole's public profile is based on her playing heroine to two pantomime villains. Often the moustache-twirling rogue is Simon Cowell, and the nation applauds; the rest of the time it's her own husband. Certainly, 3 Words is being presented as a response to those experiences. For watchers of "tormented Cheryl", there's plenty more doggedness on offer, besides the single. "We argue a lot no matter what we do," she hisses on Make Me Cry, adding: "Careful what you're saying 'cos I'm trying to stay with you." On Rain On Me she snarls:"I won't run … 'cos if you think I'm weak then that makes you strong." At times like those, 3 Words seems a co-dependents' manifesto: on the jaunty Happy Hour the metaphor for a relationship is that classic romantic standby, alcohol addiction.

But whether you care about her marriage or not, all this anxiety and defiance makes for a low-key, shadowy kind of pop record, whose best songs rarely take immediate hold. Its most upbeat moments are its weakest: Will.I.Am and Cheryl lumbering on to the disco floor on Heaven, and the tinny electropop of Taio Cruz's contribution, Stand Up. Elsewhere the main sound on 3 Words is R&B, with any rhythmic trickery stripped out. When it works, as on Parachute, you end up with an austere take on modern pop that gives Cole's voice the space it needs. When it doesn't, songs such as Don't Talk About This Love just end up sounding a bit cheap. Confirmation that this is a recession-era pop album comes with the make-do-and-mend inclusion of Heartbreaker, Will.I.Am's solo hit from last year, billed now as a Cole track despite her contribution amounting to 30 seconds of backing vocals.

The album may disappoint Cole's oldest fans. At its best, Girls Aloud's work with the Xenomania production team was smart, inventive and delightful. As a clean break with the Girls Aloud sound, 3 Words at first sounds like a throwback to the 90s, when acts like Louise Redknapp would put us to sleep with their unshakeably nice R&B lite.

Parts of this album never pass beyond conservative pleasantries. But the shift in sound was still necessary. The typical Xenomania production sound, as heard this autumn on Mini Viva's I Left My Heart in Tokyo, is too busy and shrill for Cole's voice to carry alone. She's not as full a singer as the belters and divas she presides over each week, but she's an expressive performer and a less showy backing lets that come through. Her showcase is the album's title track, built on dark loops of treated acoustic guitar and building into a claustrophobic dance track. It's as brave and novel a song as anything Cole's group have released, and shows how good she can be given a more imaginative setting. Most of 3 Words doesn't provide that: it's ultimately too tentative and slight to be more than a footnote in Cheryl Cole's unstoppable celebrity story.